The present invention relates to a desk top cleaner for cleaning fine dust from the top of a desk or table.
In the prior art, a cleaner of this kind is exemplified by both a cleaner for adhering dust of an eraser or the like to an adhesive layer, which is formed on the outer circumference of a roller, and cleaning it off by rotating the roller while pushing it onto the cleaning surface, and a battery type cleaner for sucking the eraser dust by using a fan actuated by a motor.
The cleaner for cleaning the dust by pushing the roller onto the cleaning surface has problems that the adhesion of the adhesive layer of the roller will drop to fail to catch the dust after use for a while and that it cannot intrinsically catch dust of large size.
On the other hand, the cleaner using the motor for sucking the dust has a problem in its high price.
A first object of the present invention is to provide a desk top cleaner inexpensively with a simple structure.
A second embodiment of the present invention is to provide a desk top cleaner which is enabled to give the user a pleasant atmosphere by the rhythmical motions of its broom.
In order to achieve the above-specified object, the desk top cleaner of the present invention provides that a crank shaft is rotatably supported in a frame; that a broom is formed with an elongated slot to engage with the crank shaft and has its upper end portion fitted in a supporting portion formed in the frame and its lower end portion is equipped with a brush; that there is provided a power transmission mechanism for transmitting a rotating force from a drive source to the crank shaft; and that a dust case for accommodating the dust swept by the broom is formed in the frame.
A plurality of brooms may be arranged in parallel with the extending direction of the crank shaft.
The drive source may be at least one wheel attached rotatably to the frame.
The power transmission mechanism is equipped with clutch means for transmitting the one-way rotation of the wheel only.
The power transmission mechanism has its rotation transmission ratio set such that the distance, by which the frame is moved forward by the angle of rotation of the wheels required for the broom to move from a cleaning start position to clear the cleaning surface and to reach the cleaning start position again, is smaller than the cleaning distance of the broom.
The elongated slot of the broom is formed at one portion with a smaller cut portion than the diameter of the crank shaft, and at least one of the members divided from the cut portion is an elastic part, the end portion being formed at the side of the cut portion with a tapered surface.
The broom is equipped at its upper end portion with an engaging portion for regulating the protruding length of the broom from the lower face of the frame.
The dust case is so supported as to rock freely with respect to the frame while having its rocking range restricted by the engaging portion and is equipped with bias means for pushing the dust entrance at its front end portion into contact with the cleaning surface, and the bias means is either a resilient portion formed integrally with one of the frame and the dust case or a moment by the force of gravity around the rocking center of the dust case.
The dust case may be formed integrally with a resilient portion to come into resilient contact with the cleaning surface.
The broom may be equipped with a weight.
The crank shaft may be capable of having its lower end face pushing the lower end portion of the broom.
One of the lower end portion of the broom or the lower end face of the crank shaft is formed integrally with a resilient portion for urging the broom resiliently downward.
The frame is equipped with a selecting member for regulating the size of dust to be swept in.
A plurality of wheels may be rotatably attached to the frame, and a belt may be made to run on the wheels. The power transmission mechanism may be interposed between one of the wheels and the crank shaft.
The drive source may be not only the wheels but also a drive motor mounted in the frame.
If the cleaner thus constructed is moved forward while being pushed onto the cleaning surface, the rotation of the wheel is transmitted to rotate the crank shaft so that the broom is rocked to sweep the dust on the desk top into the dust case.
In case the cleaner is backed, the clutch means terminates the rotation transmission from the wheel to the crank shaft so that the broom is not moved and the dust is not swept back onto the cleaning surface.
Since the rotation transmission ratio is set at the above-specified value, the desk top is not left unswept.
Since the crank shaft is inserted from the cut portion into the elongated slot of the broom, the assembly is facilitated, and unnecessary upward motions of the broom are eliminated.
Since the broom is formed with the engaging portion, it does not protrude downward, if unnecessary, even if the cleaner body is lifted up, to avoid the disadvantages that the broom cannot be rocked or is damaged.
Since the brush at the lower end portion of the broom and the dust entrance of the dust case are pushed to contact the cleaning surface, the dust swept by the broom is smoothly carried into the dust case.
The dust of a size to be carried in is selected by the selecting member so that oversize dust is prevented from invading into the cleaner.
If the belt is made to run on plural belts, the power generated by the advance of the cleaner is transmitted without fail to the crank shaft.